志愿者们用通俗易懂的语言帮助老年人提高金融素养。(by means of)

Volunteers help elderly people improve their financial literacy by means of easy-to-understand language.

考查短语和时态。“志愿者们” 翻译为volunteers，在句中作主语；“用 (……的方法)” 用短语by means of；“通俗易懂的语言” 翻译为easy-to-understand language；“帮助某人做某事” 用短语help sb. do sth.；“老年人” 翻译为elderly people；“提高金融素养” 翻译为improve their financial literacy。陈述客观事实，用一般现在时。故翻译为：“Volunteers help elderly people improve their financial literacy by means of easy-to-understand language.”。